<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
	<style type="text/css">
			/*设置背景图*/
			body{
				background-image:
				url(../images/background.png);
				background-repeat:repeat-y;
				background-position:center;
				
			}
			div{
				width:125px;
				height:125px;
				border:1px solid red;
				margin:10px auto;
			}
			/*采用简化的方式设置背景
			background:颜色 图片 平铺 位置
			上述4个属性可以酌情省略
			*/
			.enemy{
				background:
				url(../images/airplane.png)
				no-repeat center;
				
			}
			.hero{
			background:
			url(../images/hero0.png)
			no-repeat center;
			}
			/*
				固定背景图
			*/
			body{
				background-attachment:fixed;
			}
						
	</style>
</head>
<body>
	<div class="enemy"></div>
	<div class="enemy"></div>
	<div class="enemy"></div>
	<div class="enemy"></div>
	<div class="enemy"></div>
	<div class="enemy"></div>
	<div class="enemy"></div>
	<div class="enemy"></div>
	<div class="enemy"></div>
	<div class="enemy"></div>
	<div class="hero"></div>
	<div class="hero"></div>
</body>
</html>